The objectives of this investigation are: to determine whether specific types of human papilloma viruses (HPV) are causally related to intraepithelial and invasive cervical neoplasia; if so, to identify circumstances under which this carcinogenic effect occurs; and to clarify the role of male sexual behavior and use of prostitutes in the etiology of cervical cancer and in transmission of the specific types of HPVs that may be of etiologic importance in this disease. A hospital-based case-control study in Bangkok, Thailand is proposed. Approximately 300 cases, 300 hospital controls, and 300 clinic controls will be studied, plus 80 controls from a family planning clinic and 50 controls from among women with a hysterectomy for non-neoplastic conditions. These women's current husbands will also be studied, as will 200 prostitutes. All subjects will be interviewed to ascertain information on sexual behavior, contraceptive practices, smoking, and other factors that may confound or modify associations between HPV and cervical cancer. Serum specimens from all subjects will be obtained for determinations of antibodies against human immunodeficiency virus, hepatitis B virus, and herpes simplex virus type 2. Fresh tissue specimens from the tumors of the cases and the normal cervices of the hysterectomized controls, cervical scrapings from all women, and penile swabs from the husbands will be obtained and analyzed for specific types of HPV DNA using polymerase chain reaction techniques. Relative risks of invasive and intraepithelial cervical neoplasia will be estimated in relation to various indices of male and female sexual behavior, and specific types of HPV; and interactions between HPV infections and such potentially modifying factors as age, steroid contraceptives, smoking, and other viral infections will be investigated. Also, the prevalence of specific types of HPV DNA will be compared in the husbands of cases and controls, the husbands and their wives, and the husbands and the prostitutes, to determine whether the same types of HPV that are related to cervical cancer are prevalent in prostitutes, and sexually transmitted.